Cable retaining clamps are typically used in the installation of antennas and the like to secure the antenna cable to a support structure. Often, the support structure is a tall tower and the cable is mounted to the tower at several locations between the base and top of the tower. The retaining clamp used to mount the cable to the support structure must securely hold the cable in place and must not damage the cable. Conventionally, cables were installed using a variety of hardware requiring the attachment of bolts, screws or other fasteners to the support structure. Considerable time and effort is required to mount such conventional fasteners to the support structure, increasing the installation expense and prolonging the exposure of the installer to unsafe working conditions.
Cable hangers for mounting a cable to a support structure without the use of the time-consuming fasteners are available. U.S. Pat. No. 4,763,132 discloses an example of a cable hanger for an elliptical waveguide in which the legs of the hanger are slipped around the waveguide and snapped into a hole in the support structure. Detents on the exterior of the hanger legs engage the surface of the support structure adjacent the hole to resist extraction of the hanger from the hole. The disclosed hanger may be installed in a one step without the use of time consuming fasteners. However, the hanger will not adequately engage the support structure unless the detents contact the surface of the support structure. To ensure this contact occurs, both the holes formed in the support structure and the detents must meet strict tolerances. However, the holes drilled in the support structure and the surface of the support around the hole often include protuberances or other irregularities which interfere with the ability of the detents to adequately engage the support structure. Forming the detents to the necessary tolerances on the exterior of the legs increases the cost of manufacture of the hanger.
U.S. Pat. No. 5,393,021 discloses another example of a cable hanger which is snapped into a hole formed in the support structure. The cable is inserted into cable retention section of the hanger, and the legs of the cable retention section are inserted into the hole in the support structure. The side edges of each leg is provided with a locking barb which engages the inner surface of the support structure. The exterior of the legs are concave in shape, opposite the circular contour of the hole, such that the barbs contact the support structure at four discrete locations. This method of attachment is intended to provide contact between at least some of the barbs and the support structure even when there are irregularities in the hole or the surface of the support structure. However, the amount of engagement between the barbs and the support structure is limited. If any of the barbs or leg portions become bent or damaged during shipping and handling, the locking members of the hanger may not function properly.
A cable retaining clamp which may be used to securely and efficiently mount a cable to a support structure is desirable. A cable retaining clamp which engages extended portions of the support surface around the hole is also desirable. Similarly, a cable retaining clamp which engages the support structure at a location spaced from the perimeter of the aperture is desirable. Furthermore, a cable retaining clamp which may be economically manufactured would be of particular advantage.